3rd generation partnership project (3GPP) is working to define the SR-VCC procedures in Release 8. Stage 2 of SR-VCC is defined e.g. in 3GPP TS 23.216. SR-VCC may enable a user equipment (UE) to perform an inter-domain handover from long term evolution (LTE) to circuit switched (CS). In this way, the voice over internet protocol (VoIP) session over IP multimedia subsystem (IMS) over the LTE access can be transferred to the CS network, when the LTE coverage is getting weaker.
FIG. 1 shows a domain transfer from the LTE (VoIP) to 2nd generation/3rd (2/3G) CS access as defined e.g. by Release 8 SR-VCC. As shown in FIG. 1, a communication network 100 comprises a user-actuated UE 101 capable of LTE packet switching (PS) and VoIP, a network 102 having both a LTE radio network and a 2G/3G generation CS network, and the internet 103. In turn, the network 102 comprises a mobility management entity (MME) 1021, a mobile switching center server (MSS) 1022, a database 1023 for providing user data for both packet switched and circuit switched entities.
The transfer to the CS side is controlled by the network 102, and the terminal/UE 101 is aware of the situation only when the UE 101 is commanded to hand over to the 2/3G CS-access. For enabling the routing to the correct mobile switching center server (MSS) 1022, home location register (HLR) information is updated after the handover is completed.
Release 8 defines also an IMS centralized services (ICS) functionality. With this functionality, the CS-access of the UE 101 can be adapted to the IMS environment with enhanced MSS (eMSS) functionality. The information is received during the location updating toward the HLR. Based on the HLR information the MSS can initiate ICS functionalities toward the IMS. In other words, Release 8 defines an ICS functionality which allows the CS access of the UE 101 to be adapted to IMS environment via an ICS enhanced MSC server (IMSC). Accordingly, the IMSC may have a direct SIP communication with IMS core network. The information, whether a subscriber is an ICS subscriber, is received from the HLR during the location updating after the handover. Based on this information, the ICS functionality can be initiated.
In consideration of the above, according to examples of the present invention, methods, apparatuses, a system, related computer programs and data structures for subscription information delivery are provided.
According to an example of the present invention, in a first aspect, this object is for example achieved by a method comprising:                transmitting, during terminal attachment to evolved packet system and in at least a portion of a diameter command, centralized service-related subscription information.        
According to further refinements of the example of the present invention as defined under the above first aspect,                the diameter command is an insert subscriber data request command and the portion is one of a subscription data attribute value pair and an extension of a subscription data attribute value pair;        the transmitting is performed responsive to receiving a diameter request for the centralized service-related subscription information;        the method further comprises receiving, prior to the transmitting, the diameter request for the centralized service-related subscription information;        the diameter request is an update location request command;        the diameter command is an update location answer command and the portion is one of a subscription data attribute value pair and an extension of a subscription data attribute value pair;        the diameter command further comprises an indication of the centralized service-related subscription information.        
According to an example of the present invention, in a second aspect, this object is for example achieved by a method comprising:                transmitting, in an initial message of a call continuity procedure, received centralized service-related subscription information.        
According to further refinements of the example of the present invention as defined under the above second aspect,                the method further comprises receiving the centralized service-related subscription information during terminal attachment to evolved packet system;        the centralized service-related subscription information is received constituting at least a portion of a diameter command;        the diameter command is an insert subscriber data request command and the portion is one of a subscription data attribute value pair and an extension of a subscription data attribute value pair;        the diameter command is an update location answer command and the portion is one of a subscription data attribute value pair and an extension of a subscription data attribute value pair.        
According to an example of the present invention, in a third aspect, this object is for example achieved by a method comprising:                operating according to centralized service-related subscription information received in an initial message of a call continuity procedure.        
According to further refinements of the example of the present invention as defined under the above third aspect,                the method further comprises receiving the initial message of the call continuity procedure;        the operating comprises one of operating as mobile switching center server enhanced for centralized services and operating as basic mobile switching center server enhanced for the call continuity procedure.        
According to further refinements of the example of the present invention as defined under the above second and third aspects,                the initial message further comprises an indication of the centralized service-related subscription information.        
According to further refinements of the example of the present invention as defined under the above first to third aspects,                the initial message is constituted by a packet switched to circuit switched request;        the initial message is constituted by a single radio voice call continuity packet switched to circuit switched request;        the initial message is transmitted via a general packet radio service tunneling protocol interface;        the call continuity procedure is constituted by a single radio voice call continuity procedure;        the centralized service-related subscription information relates to internet protocol multimedia subsystem centralized services;        the centralized service-related subscription information constitutes an additional information element in the initial message.        
According to an example of the present invention, in a fourth aspect, this object is for example achieved by an apparatus comprising:                a transmitter configured to transmit, during terminal attachment to evolved packet system and in at least a portion of a diameter command, centralized service-related subscription information.        
According to further refinements of the example of the present invention as defined under the above fourth aspect,                the diameter command is an insert subscriber data request command and the portion is one of a subscription data attribute value pair and an extension of a subscription data attribute value pair;        the transmitter is further configured to transmit responsive to receiving a diameter request for the centralized service-related subscription information;        the apparatus further comprises a receiver configured to receive, prior to the transmitting performed by the transmitter, the diameter request for the centralized service-related subscription information;        the diameter request is an update location request command;        the diameter command is an update location answer command and the portion is one of a subscription data attribute value pair and an extension of a subscription data attribute value pair;        the diameter command further comprises an indication of the centralized service-related subscription information;        the apparatus is constituted by one of a home location register and a home subscriber server.        
According to an example of the present invention, in a fifth aspect, this object is for example achieved by an apparatus comprising:                a transmitter configured to transmit, in an initial message of a call continuity procedure, received centralized service-related subscription information.        
According to further refinements of the example of the present invention as defined under the above fifth aspect,                the apparatus further comprises a receiver configured to receive the centralized service-related subscription information during terminal attachment to evolved packet system;        the centralized service-related subscription information is received constituting at least a portion of a diameter command;        the diameter command is an insert subscriber data request command and the portion is one of a subscription data attribute value pair and an extension of a subscription data attribute value pair;        the diameter command is an update location answer command and the portion is one of a subscription data attribute value pair and an extension of a subscription data attribute value pair;        the apparatus is constituted by a mobility management entity.        
According to an example of the present invention, in a sixth aspect, this object is for example achieved by an apparatus comprising:                an operator configured to operate according to centralized service-related subscription information received in an initial message of a call continuity procedure.        
According to further refinements of the example of the present invention as defined under the above sixth aspect,                the apparatus further comprises a receiver configured to receive the initial message of the call continuity procedure;        the operating comprises one of operating as mobile switching center server enhanced for centralized services and operating as basic mobile switching center server enhanced for the call continuity procedure;        the apparatus is constituted by an enhanced mobile switching center server.        
According to further refinements of the example of the present invention as defined under the above fifth and sixth aspects,                the initial message further comprises an indication of the centralized service related subscription information.        
According to further refinements of the example of the present invention as defined under the above fourth to sixth aspects,                the initial message is constituted by a packet switched to circuit switched request;        the initial message is constituted by a single radio voice call continuity packet switched to circuit switched request;        the transmitter is configured to transmit the initial message via a general packet radio service tunneling protocol interface;        the call continuity procedure is constituted by a single radio voice call continuity procedure;        the centralized service-related subscription information relates to internet protocol multimedia subsystem centralized services;        the centralized service-related subscription information constitutes an additional information element in the initial message;        at least one, or more of a transmitter, an operator and the apparatus is implemented as a chipset or module.        
According to an example of the present invention, in a seventh aspect, this object is for example achieved by an apparatus comprising:                means for transmitting, during terminal attachment to evolved packet system and in at least a portion of a diameter command, centralized service-related subscription information.        
According to further refinements of the example of the present invention as defined under the above seventh aspect,                the diameter command is an insert subscriber data request command and the portion is one of a subscription data attribute value pair and an extension of a subscription data attribute value pair;        the means for transmitting is further configured to transmit responsive to receiving a diameter request for the centralized service-related subscription information;        the apparatus further comprises means for receiving, prior to the transmitting performed by the means for transmitting, the diameter request for the centralized service-related subscription information;        the diameter request is an update location request command;        the diameter command is an update location answer command and the portion is one of a subscription data attribute value pair and an extension of a subscription data attribute value pair;        the diameter command further comprises an indication of the centralized service-related subscription information;        the apparatus is constituted by one of a home location register and a home subscriber server.        
According to an example of the present invention, in an eighth aspect, this object is for example achieved by an apparatus comprising:                means for transmitting, in an initial message of a call continuity procedure, received centralized service-related subscription information.        
According to further refinements of the example of the present invention as defined under the above eighth aspect,                the apparatus further comprises means for receiving the centralized service-related subscription information during terminal attachment to evolved packet system;        the centralized service-related subscription information is received constituting at least a portion of a diameter command;        the diameter command is an insert subscriber data request command and the portion is one of a subscription data attribute value pair and an extension of a subscription data attribute value pair;        the diameter command is an update location answer command and the portion is one of a subscription data attribute value pair and an extension of a subscription data attribute value pair;        the apparatus is constituted by a mobility management entity.        
According to an example of the present invention, in a ninth aspect, this object is for example achieved by an apparatus comprising:                means for operating according to centralized service-related subscription information received in an initial message of a call continuity procedure.        
According to further refinements of the example of the present invention as defined under the above ninth aspect,                the apparatus further comprises means for receiving the initial message of the call continuity procedure;        the operating comprises one of operating as mobile switching center server enhanced for centralized services and operating as basic mobile switching center server enhanced for the call continuity procedure;        the apparatus is constituted by an enhanced mobile switching center server.        
According to further refinements of the example of the present invention as defined under the above eighth and ninth aspects,                the initial message further comprises an indication of the centralized service-related subscription information.        
According to further refinements of the example of the present invention as defined under the above seventh to ninth aspects,                the initial message is constituted by a packet switched to circuit switched request;        the initial message is constituted by a single radio voice call continuity packet switched to circuit switched request;        the means for transmitting is configured to transmit the initial message via a general packet radio service tunneling protocol interface;        the call continuity procedure is constituted by a single radio voice call continuity procedure;        the centralized service-related subscription information relates to internet protocol multimedia subsystem centralized services;        the centralized service-related subscription information constitutes an additional information element in the initial message;        at least one, or more of means for transmitting, means for operating and the apparatus is implemented as a chipset or module.        
According to an example of the present invention, in a tenth aspect, this object is for example achieved by a system comprising:                an apparatus according to the above fourth and seventh aspects;        an apparatus according to the above fifth and eighth aspects; and        an apparatus according to the above sixth and ninth aspects.        
According to an example of the present invention, in an eleventh aspect, this object is for example achieved by a computer program embodied on a computer readable medium, comprising code means for performing a method comprising:                transmitting, during terminal attachment to evolved packet system and in at least a portion of a diameter command, centralized service-related subscription information.        
According to an example of the present invention, in a twelfth aspect, this object is for example achieved by a computer program embodied on a computer readable medium, comprising code means for performing a method comprising:                transmitting, in an initial message of a call continuity procedure, received centralized service-related subscription information.        
According to an example of the present invention, in a thirteenth aspect, this object is for example achieved by a computer program embodied on a computer readable medium, comprising code means for performing a method comprising:                operating according to centralized service-related subscription information received in an initial message of a call continuity procedure.        
According to an example of the present invention, in a fourteenth aspect, this object is for example achieved by a data structure comprising:                at least a portion of a diameter command for conveying centralized service-related subscription information.        
According to further refinements of the example of the present invention as defined under the above fourteenth aspect,                the diameter command is an insert subscriber data request command and the portion is one of a subscription data attribute value pair and an extension of a subscription data attribute value pair;        the diameter command is an update location answer command and the portion is one of a subscription data attribute value pair and an extension of a subscription data attribute value pair.        
According to an example of the present invention, in a fifteenth aspect, this object is for example achieved by a data structure comprising:                an initial message of a call continuity procedure comprising received centralized service-related subscription information.        
In this connection, the example of the present invention enables one or more of the following:                The HLR information may be updated prior to completion of the handover, so as to avoid that the terminal's information is different from the HLR information and to avoid unsuccessful call attempts.        No need for the anchoring call to IMS to be routed through the PSTN as a CS break-in call. In addition, there is no need for any communication using other protocols like bearer independent call control (BICC) or integrated service digital network (ISDN) user part (ISUP) and possibly involving a media gateway control function (MGCF) as a session initiation protocol (SIP) converter in the routing path.        The ICS can be started during the handover, because the subscriber information is received prior to completion of the handover procedure.        
According to an exemplary embodiment of the present invention there is provided an apparatus, comprising a transmitter configured to transmit, during terminal attachment to evolved packet system and in at least a portion of a diameter command, centralized service-related subscription information, wherein at least one, or more of a transmitter, an operator and the apparatus is implemented as a chipset or module.
According to an exemplary embodiment of the present invention there is provided an apparatus, comprising a transmitter configured to transmit, in an initial message of a call continuity procedure, received centralized service-related subscription information, wherein at least one, or more of a transmitter, an operator and the apparatus is implemented as a chipset or module.
According to an exemplary embodiment of the present invention there is provided an apparatus, comprising an operator configured to operate according to centralized service-related subscription information received in an initial message of a call continuity procedure, wherein at least one, or more of a transmitter, an operator and the apparatus is implemented as a chipset or module.